Details

• Seminar begins at 10:30 a.m. each Friday during the academic year and is expected to run 1 hour.
• Location: Corless Auditorium, 215 S Ferry Rd, Narragansett, RI 02882
• Please join us for a bagels and coffee reception prior to the event at 10 a.m. in the Trident Room. 
• Seminar speakers are often prepared to meet with students, staff, and faculty in the afternoon following their seminar. Please contact us if you are interested in meeting with the speaker. 

Antarctic Meltwater alters Future Projections of Climate and Sea Level

Dr. Shaina Sadai, Five College Association, 10/17/25

Imperfect understanding of ice sheet-climate interactions poses challenges for projecting the impacts of ice sheet mass loss on future climate and sea level. New research investigates ice sheet-climate dynamics by coupling a dynamic Antarctic ice sheet model and global climate model with offline coupling to a global sea level model. In our single-model, single-member modeling framework, we find sea level and climate projections are significantly modified from uncoupled simulations neglecting Antarctic meltwater under RCP8.5 and RCP4.5. Antarctic meltwater yields surface air temperatures up to 1.5°C higher in parts of the Northern Hemisphere, while broadly dampening temperature rise in the Southern Hemisphere. Due to radiative feedback changes, both emissions scenarios have global mean surface temperature warming ~0.3°C lower in the coupled scenario than the control by 2100, with a maximum anomaly of ~1°C at 2200 under RCP8.5. This slows Antarctica’s contribution to global mean sea level rise. Total Antarctic sea level contributions under RCP8.5 include substantial contributions from East Antarctica, though not under RCP4.5. We further find that regionally, projected sea level is up to 0.9 m higher in the Pacific than the global mean Antarctic contribution under RCP8.5 at 2200.

Oceanic influences of the Drygalski Ice Tongue in Terra Nova Bay: an observational perspective

Liv Cornelissen, Ph.D. student at The University of Auckland, 6/30/25

The Drygalski Ice Tongue (DIT), located in the western Ross Sea, is the largest remaining ice tongue and forms the southern boundary of Terra Nova Bay (TNB) and enables it to operate as a polynya by preventing the transport of sea ice into the bay from the south. The surrounding water masses interact with the DIT, and changes in their properties can influence the tongue’s stability. In this talk, I will present findings from a decade-long hydrographic mooring timeseries (DITx), deployed near the DIT and in the Drygalski Trough. This dataset captures variability across interannual, seasonal, and polynya-event timescales. Water masses that are formed in Terra Nova Bay and are observed near the DIT are high salinity shelf water (HSSW), TNB ice shelf water (ISW) and Antarctic surface water (ASW) and form the seasonal cycle. The interannual variability is particularly evident in the timing of seasonal transitions and in long-term temperature and salinity trends. I will also discuss the connectivity between the DITx record and other regional datasets, including Mooring D and ARGO floats.

Fine Scale Ocean Features influence the Spatial Structure of a Coastal Marine Food Web

Dr. Jacquelyn Veatch, WHOI on 2/14/25

The patchy distribution of prey in marine environments has a large effect on upper trophic level foraging strategies and distributions. While currents can disperse or concentrate low-motility plankton into patches that reflect the dynamic fluid environments they inhabit, it remains unclear whether surface flows affect motile zooplankton.Here, we used an in-situ optical dataset to detect phytoplankton patches, active acoustics to observe krill, and GPS-tagged penguins to observe three levels of the food web. These data allowed us to investigate whether the local food web overlaps with small-scale surface transport patterns as evidence that dynamic flows structure marine food webs. In Palmer Deep Canyon, Antarctica, we deployed High Frequency radars to measure hourly ocean surface currents, which were subsequently applied to estimate attractive Lagrangian Coherent Structures. We found that phytoplankton patches, Antarctic krill (Euphausia superba), Adélie penguins (Pygoscelis adeliae) and gentoo penguins (Pygoscelis papua) were preferentially located in attracting Lagrangian Coherent Structure features. These results provide evidence that Lagrangian Coherent Structures act as hotspots for prey and associated foraging predators, thus spatially focusing the food web. Results highlight the role of small-scale currents in food web focusing and the importance of transport features in maintaining the Palmer Deep Canyon ecosystem.

Dynamics of the Beaufort Gyre in a Changing Arctic

Dr. Mary-Louise Timmermans, Yale University, 9/26/25

The Beaufort Gyre circulation system is a central part of the Arctic climate undergoing significant change across all environmental parameters. The talk presents two decades (2003-2024) of intensive observations in the Beaufort Gyre to characterize its evolving freshwater and heat content, which are related to wind forcing modulated by the presence of sea ice. Following a period of sustained freshwater and heat accumulation in the first half of the record, freshwater and heat content have been declining in recent years. Trends indicate that prevailing winds are becoming less effective at spinning up the gyre and accumulating freshwater. This shift in wind forcing outweighs the influence of a weakening sea-ice pack, which is becoming less effective at spinning down the gyre. We place these findings within the broader context of Arctic change, which can help inform future projections.

Expanding Ocean Observing Systems for Weather and Climate: From the Northeast US to the Caribbean Sea

Dr. Travis Miles, Rutgers University, 10/31/25

Over the past three decades in situ ocean observing capabilities have expanded rapidly, becoming robust multi-platform networks capable of supporting broad stakeholder needs with real-time data delivery. In parallel, the Global Ocean Observing System (GOOS) has been focused on connecting those networks with stakeholders from local communities, regional and global forecasting systems, and multi-disciplinary research teams. In this presentation I will broadly discuss the 1) growth and implementation of the hurricane glider network from the Northeast US through the Caribbean; 2) the impacts of upper ocean observations on operational ocean forecasting during hurricanes; and 3) exploration of new findings of climate trends in the Caribbean Sea.

The role of Super-Inertial Coastally Trapped Waves in Tidal Energy Pathways

Dr. Ruth Musgrave, Dalhousie University, 12/6/24

In this talk I will discuss tidal energy pathways with a focus on the role of coastally trapped waves. In particular, I will describe the generation of super-inertial coastally trapped waves by the scattering of low-mode internal tides at a corrugated shelf break. These “leaky” waves are coupled to freely propagating inertia-gravity waves, but have the potential to carry energy far along the coastal boundary. These waves tend to have small vertical and horizontal scales, and their generation has implications for the dissipation of tidal energy at coastal boundaries.

Where Glaciers meet the Ocean: testing theories for Submarine Melt with Observations from Autonomous Vessels

Dr. Rebecca Jackson, Tufts University, 10/4/24

Around the globe, glaciers and ice sheets are shrinking, raising sea levels at an accelerating rate.

Ocean warming has been implicated as a driver of glacier retreat, with submarine melting as the

presumed link. However, at the termini of tidewater glaciers – where glaciers meet the ocean with a near-vertical ice cliff – we lack observations of submarine melting or the oceanic processes that control melt. Instead, many studies rely on untested theory and parameterizations to estimate submarine melt rates. These frameworks often hinge on buoyant plumes, whose small-scale dynamics can modulate both the ocean’s impact on the glacier via submarine melting and the glacier’s impact on the ocean via freshwater input. In this talk, I will present data collected near the terminus of LeConte Glacier, Alaska. Autonomous vessels surveyed and deployed moorings near the glacier, in a region that is otherwise inaccessible due to iceberg hazards, while simultaneous measurements were collected downstream with a ship and upstream on the glacier. We assess the structure and dynamics of an upwelling plume, the internal wave field that the plume excites, and the links between plumes, submarine melting, and glacier dynamics. We propose modifications to the standard approach for parameterizing melt, aiming to improve models of ocean-glacier interactions and work towards more accurate projections of sea level rise.